The announcement that Chief Justice Andrew Li Kwok-nang would resign in a year's time was almost a bombshell, because it was totally unexpected. He explained his decision philosophically by quoting the Bible, saying: 'There is a time for everything and there is a season for every activity under heaven'. But why next year, people still wonder, even though he denies there are any political or health reasons.

There are no grounds, though, for any speculation. Public attention should now focus on the succession issue and how to maintain the vibrancy of the judiciary.

Li took over as chief justice upon the establishment of the special administrative region. Under his leadership, the judiciary has enjoyed higher credibility than the government, the legislature, political parties and even the mass media. Judging from the overwhelming praise accorded to him by all sectors of society and across the political spectrum, there is no doubt that he has inspired immense public trust and confidence with his firm commitment to legal principles and the independence of the judiciary, and his great passion for Hong Kong.

He epitomises a strong judiciary that has come of age and grown into a sustainable system supported by a competent legal profession. Irrespective of what some mainland academics or officials say, Hong Kong practises the 'separation of powers'. To many in the community and in business, the rule of law is one of the defining pillars of the Hong Kong system under 'one country'.

Amid major Chinese cities aspiring to be world class, only Hong Kong matches the standing of global metropolises like London and New York, thanks partly to its rule of law and judicial independence. For ordinary people, the judiciary provides an effective check on administrative abuse or unreasonable decisions.

Indeed, the Basic Law accords a broader interpretation of judicial review than that under common law, conferring citizens the right to institute legal proceedings against any acts of the executive authorities.

Since the handover, social groups and politicians have increasingly used the courts as the new arena to force the government to delay or overturn policy, or to enhance their position in political bargaining. Some worry the political battle has now been taken to the courtroom, but Hong Kong is not alone among common-law jurisdictions in confronting a rising number of judicial review cases.

The judiciary has so far been reluctant to be drawn into policy controversies. The chief justice has emphasised repeatedly that the courts are only concerned with the legality of the decision, and could not possibly provide a panacea for various political, social and economic problems.

Still, 'politicisation' will not disappear even if the government is fully responsive and democratic, because the interactive nature of politics has already made judicial review more of a political than a judicial venue for agitation for change, posing a continuing challenge to Li's successor and fellow judges.

Although Li said his departure, three years ahead of the normal retirement age of 65, was to facilitate orderly succession planning in the judiciary in the coming years, it is not entirely necessary or appropriate for the future chief justice to 'pick his new team', as the media put it, even though he heads the Judicial Officers Recommendation Commission.

While the chief executive appoints judges, and the legislature has the power to endorse the appointment of the judges of the Court of Final Appeal and the chief judge of the High Court, judicial appointments are not political appointments. They are based on the recommendation of the Judicial Officers Recommendation Commission, so as to avoid any political or ideological preference, as is often the case in the US. Neither does the legislature scrutinise judicial candidates in the same way as the American Senate.

To safeguard their independence, judges should be appointed on merit, integrity and experience, with no regard to their political inclinations, or to whoever is chief justice. Admitting judges from different backgrounds to the Court of Final Appeal and senior courts enriches the judicial process.

Anthony Cheung Bing-leung is an executive councillor and founder of SynergyNet, a policy think tank